This disclosure relates generally to processes for removing photoreceptor coatings from a substrate, wherein the photoreceptor coatings disposed over a substrate of an electrophotographic photoreceptor. More specifically, the invention discloses a photoreceptor coatings removal process comprises subjecting an electrophotographic photoreceptor to a stripping solution that separates the coatings from the substrate.
According to one aspect of the disclosed invention, there is provided methods for recycling or remanufacturing electrophotographic photoreceptors.
In electrophotography, the substrate for photoreceptors in a rigid drum format is required to be manufactured with high dimensional accuracy in terms of straightness and roundness, optimum surface reflectance and roughness, and desired thickness. In order to obtain such a dimensional accuracy, the substrate surface is polished at a high accuracy by using sand blustering, glass bean honing, or a diamond tool and/or the like. Once the substrate surface is formed, at least one coating of photosensitive material is applied to the substrate, which may comprise a charge generation layer and a charge transport layer, or their blended in a single layer, to form a full photoreceptor device.
The fabricated photoreceptor devices are expected to have good electrical and mechanical performance in a copier or printer. But, due to complexity of the manufacturing process, it is unavoidable to have varieties of defects in some photoreceptor devices which may meet the quality requirements for the copier or printer. The defective devices have to be rejected. In another aspect, each photoreceptive device has limited application life. Once the photoreceptor device cannot function well in the machine, it is also the end of the application life of the device. These used photoreceptor devices were usually disposed in the same way as the defective devices were treated. Disposal of the device could be very costly and could cause lots of environmental issues.
Thus, there exists a need to reduce the cost of remanufacturing electrophotographic photoreceptors, for example, by recycling the non-usable photoreceptor devices, through removing the photosensitive or coating layers without damaging the substrate formation. This not only reduces the cost of producing the photoreceptor, but also decreases the cost for disposing all related materials in the devices.
Conventional photoreceptors and their materials are disclosed in Katayama et al., U.S. Pat. No. 5,489,496; Yashiki, U.S. Pat. No. 4,579,801; Yashiki, U.S. Pat. No. 4,518,669; Seki et al., U.S. Pat. No. 4,775,605; Kawahara, U.S. Pat. No. 5,656,407; Markovics et al., U.S. Pat. No. 5,641,599; Monbaliu et al., U.S. Pat. No. 5,344,734; Terrell et al., U.S. Pat. No. 5,721,080; and Yoshihara, U.S. Pat. No. 5,017,449, which are herein all incorporated by reference.
More recent photoreceptors are disclosed in Fuller et al., U.S. Pat. No. 6,200,716; Maty et al., U.S. Pat. No. 6,180,309; and Dinh et al., U.S. Pat. No. 6,207,334, which are all herein incorporated by reference.
Conventional undercoat or charge blocking layers are also disclosed in U.S. Pat. No. 4,464,450; U.S. Pat. No. 5,449,573; U.S. Pat. No. 5,385,796; and Obinata et al, U.S. Pat. No. 5,928,824, which are all herein incorporated by reference.
The terms used to describe the imaging members, their layers and respective compositions, may each be used interchangeably with alternative phrases known to those of skill in the art. The terms used herein are intended to cover all such alternative phrases.